On my Plesk installation the Horde themes are installed to /usr/share/psa-horde
I downloaded the wps_sober theme.
To install it:
– extract all the files of the archive to the /usr/share/psa-horde/ directory (Extract files directly to that dir, not to /usr/share/psa-horde/wps_sober !)
– if you want your users to use this theme by default, edit the file /etc/psa-horde/horde/prefs.php and check for the line 299 -> put ‘wps_sober’ in replacement of ‘bluewhite’ ORĀ
– create a symbolic link from the default theme to the wps_sober theme
That’s it! You got a really better-looking skin that won’t scare your users.